Workpiece holding or journalling member for machine tools



Jan. 27, '1959 W. NEUKOMM M 2,870,894

WORKPIECE HOLDING 0R JOURNALLING MEMBER FOR MACHINE TOOLS Filed Jan. 21, 1954 //V VEA/To@ #V4/.TER

/vEuA/o Mn 2,870,894 Patented Jan. 27, 1959 WORKPIECE HOLDING OR JURNALLING MEMBER FOR MACHINE T0015 Walter Neukomm, Moutier, Switzerland, assignor to Frederic Neukomm, Court, Switzerland Application January 21, 1954, Serial No. 405,481 Claims priority, application Switzerland February 6, 1953 1 Claim. (Cl. 193-1) The present invention relates to a member for supporting and centering workpieces in lathes and other machine tools, this member being split over part of its length and having a longitudinal bore.

In known members of this kind the slits extend in the longitudinal direction, i. e. parallel to the axis of the bore.

If the member has e. g. four slits evenly divided over its circumference, then, if e. g. a prismatic workpiece (bar) should be supported while being machined, it may happen that a longitudinal edge of the workpiece engages that portion of one of the slits which is immediately adjacent to the bore, whereby the workpiece may temporarily reach an eccentric position, so that the passages of the longitudinal edges at the slits may provoke troublesome vibrations.

The main object of the invention is to avoid these draw backs, this being achieved by having the slits extend at an angle with regard to the longitudinal direction of the member over at least a part of their length.

In a preferred embodiment the slits are helical.

The accompanying drawings represent, by way of example, two embodiments of the invention.

Fig. 1 is a longitudinal section view of the first embodiment constituting a journalling member.

Fig. 2 is an elevational view of this member.

Fig. 3 is an end view taken in the direction of the arrow III in Fig. 1.

Fig. 4 is a longitudinal section view of the second em bodiment constituting a chuck member.

Fig. 5 is an elevational view of this chuck member, and

Fig. 6 is an end view taken in the direction of the arrow of Fig. 4. I

The joumalling memberrepresented in Figs. l to 3 comprises a tubular body 1 having a bore 2 in the for ward portion of which a liner 3 made of hard metal is arranged and soldered or otherwise fixed. The body 1 has at its forward end an outer rearwardly directed cone 4 engaged by an inner cone of a sleeve 5, the engagement being adjustable by means of a tightening nut 6 screw ably engaging a threaded portion 7 at the rearward end of the body 1` A tenon 8 fixed to a transversal hole of the sleeve 5 engages a longitudinal groove 9 of thebody 1 to prevent a rotation of the latter relative to the sleeve 5.

Journalling members so built to allow for an adjustment of the diameter of the bore of the liner 3 are known in the art. Hitherto, however, the slits extended in the longitudinal direction, whilst in the journalling member of the invention the slits 10 extend helically in the body 1 as well as in the liner 3. Thus they extend at an angle with the longitudinal direction of the journalling member where they intersect with the bore, in particular with the bore of the liner 3, thereby providing the beneficial effect mentioned hereabove.

The chuck member 11 represented in Figs. 4 to 6 has a bore 12 and a tightening cone 13 at its forward end like most of the known chuck members. It has slits 14 in its forward half. These slits` 14, instead of being longitudinal, are helical and thus extend at an angle to the longitudinal direction of the member where they intersect the bore 12.

In both embodiments shown the slits might be inclined to the longitudinal direction only over a part of their length in the range of the bore of the liner 3 or of the bore 12. Moreover, the slits might be plane in lieu of being helical.

What I claim is:

A centering collet type bearing for a workpiece which is to be rotated in the bearing while being fed axially through the bearing comprising a collet-like structure having a bore of one diameter and a counterbore of a larger diameter coaxial therewith, the interior wall of said first bore being defined by a cylindrical bearing portion at the outer end of said structure, said structure inwardly from said outer end delining a shank within which said counterbore is defined, a series of radial slots defined in said outer end and opening through the interior wall denng said cylindrical bearing portion, said slots being angularly disposed to the longitudinal axis of said bore to prevent chatter of the workpiece rotated and centered in said cylindrical bearing portion, said slots extending into said counterbore and terminating within the axial contines thereof to provide a substantial part of said counterbore with a solid wall, the outer surface of said outer end being conical, an adjustment sleeve for said structure for adjusting said bearing structure to the workpiece to center the same as it is rotated therein said sleeve embracing said shank inwardly from said outer end and being supported for axial movement relative to said outer end to engage said outer conical surface to adjust the size of said bearing structure, and an actuating nut in screw thread engagement with one of said shank and sleeve and in axial engagement with the other of them.

2,741,483 Cox Apr. 10, 1956 

